Since we get all our info from our educators, we naturally think we are getting the whole picture and others aren't. History is always taught that way I think. It's hard for most teachers to give a world view anywhere in the world without pissing off someone locally.
No, i don't think it has anything to do with pissing off anybody... or purposely trying to deceive students. It's the fact that there are so many facet to war, you can't possibly cover EVERYTHING about it... at least not at the highschool level. So they focus on what's important to them, which is their own history and their own involvement.
Students are taught that Russia played a major role in the war... even though they might not necessary go into detail battles such as they might with the Battle of the Bulge. It's just common-sense that they would focus on what's important to their own history rather than trying to encompass everything about the war. People are taking history to learn about their own history, not about world history... that's a course in itself.
The Japanese however, do overtly lie about what they did or didn't do in the war. The Germans did worst, but they own up to it and it is taught in the school.